Freezing apparatus



J. F. FURRY ETAL FREEZING APPARATUS Fild April 15. 1959 Sept. 16, 1941.

2 Sheets-Sheet 1 INVENTOR JOHN F." FL/KZYQL BYHE'THUE D. fiME.

/ AMMM ATTORNEYQ J. F. FURRY ET AL FREEZING APPARATUS Sept. 16, 1941.

2 Sheets-Sheet 2 Filed April 15, 1939 INVENTOR JOHN F Fuzzy finer/10E .0. fYME.

/ ATTORNEY Patented Sept. 16, 19 41 FREEZING APPARATUS John F. Furry, Galesburg, and Arthur D. Ames Lake Bracken, Ill., assignors to Outboard, Ma-

rim: and Manufacturing Company, 111., a corporation of Delaware Waukegan,

Application April 15, 1939, Serial No. 268,042

12 Claims. ((162-126) This invention pertains to refrigerating apparatus of that type which utilizes a freezing chamber in association with an evaporator coil.

Objects of our invention are, to provide:

An evaporator having a double tube or counterfiow-coil arranged and adapted to equalize the temperature throughout the freezing chamber, delay the accumulation of excessive frost upon the colder portions of the tube and prevent defrosting of other portions of the tube during offcycle periods:

' An evaporator of the coiled tube type with means for trapping liquid refrigerant in the upper portion of the coil in such a manner as to permit the flow of gas through the coil, and to prevent defrosting of the upper coil surface during off-cycle periods such as would otherwise result from the natural drainage of liquid from the upper to the lowerportions of the coil:

An improved freezing chamber as a part of the evaporating unit, in which a transparent or transluscent filter wall permits illumination while excluding the heat carrying rays emanating from the source of light, and confining the admitted light to the cold rays from the blue-green end of the spectrum:

Means for checking the heat flow to a directly refrigerated portion of an evaporator chamber from a portion thereof not directly refrigerated, whereby to prevent frosting of the indirectly refrigerated portion, when relatively warm moisture carrying air comes in contact therewith; and to provide a freezing chamber housing which is easily removable from its supporting base for the purpose of cleaning both the housing and the evaporator coil or associated parts.

Further objects are. to provide: A combination with the walls of a chilling unit Figure 3 is a front view of our evaporator with parts broken away.

Figure 4 is a view in perspective of the removable portion of our freezing chamber housing.

Figure 5 is a fragmentary view in partial sec-- tion of the upper portion of one coil convolution disclosing the means of trapping liquid refrigerant therein.

Figure 6 is a fragmentary plan view in partial section of the front bottom portion of our evaporator, showing our heat check and associated portions of the coil.

Figure '7 is a view similar to Figure 5, showing a modified form of entrapping liquid refrigerant.

Like parts are identified by the same reference characters throughout the several views.

In Figures 1 and 2, our improved evaporator unit is shown as we prefer to mount it in a householdrefrigerat'or of conventional type. Our improved unit includes a conduit, preferably a feeder pipe and a tubular coil which has disposed within the convolutions thereof a base plate II, on which is removably mounted a housing I! having a door l3 secured to the front thereof by means of hinges It. The housing 12 has a light filter end plate or rear wall l5, hereinafter more particularly described. This wall may be directly connected with hangers It by bolts. I1 and I1", which also serve to connect the filter wall IS with upturned flanges of the housing base II and the shelf 20, respectively. The hangers l6 are elbowed at their upper ends and .clamped to the top II of the liner wall of the food storage chamber by clamping bolts 22. Shelf 20 is used'to support trays for ice cubes or other material to be frozen. Its front end is supported by brac ts 24 of conduit members spaced from such walls and 40 provided with liquid holding traps in their upper portions, whereby a flow of cold air may be maintained over the walls during off-cycle periods, partly by direct refrigeration due to evaporation 'of the trapped liquid, and partly by air circulation around the frosted conduits.

Means for preventing descending air, chilled by contact with the upper conduit portions, from intermixing with warmer air until it has passed below the side walls f the chilling unit.

In the drawings:

Figure 1 is a side elevation, partly in vertical section, of our improved evaporator.

Figure 2 is a plan .view of the evaporator, partially in section.

which are welded to the base plate II and; o the shelf 20 at their respective ends.

The evaporator is adapted to be employed in a refrigerator circuit having the conventional highside and low-side refrigerant areas. A conventional expansion valve 33 is employed to periodically permit a regulated flow of refrigerant from Our improved evaporator is, of--course, placed in the low-side" the high-side to the low-side.

and our feeder tube 3| is directly fed from the expansion valve.

pansion valve 33 upwardly along the rear side of the end plate l5, and then through the end plate underneath the shelf 20 in a series of laterally extending loops leading to the front end of the nected by means of a U-tube 30.

shelf, and then back along one side and through the plate |5. It then" extends downwardly and is connected to the receiving end of the coil 21.

As shown in Figures 2 and 6, the coiled portion of the conduit is of double-tube counterflow con-1 struction, and while in effect it is a continuous conduit, yet, for the purpose of distinction, coil 21 may be called the outflow coil and coil 29 the inflow or return coil. The coils are wound either in the form. of a helix or its functional equivalent in which thebottom portions of the convolutions extend obliquely. toward .the front end of the unit, and the other portions of. the coil are in a plane normal to the axis of the unit. At the front portion of the unit, the coils are intercon- The tube 29 follows the convolutions of the tube v 21 from the front to the rear end of the unit and the two tubes are soldered or otherwise secured together to provide rigidity by mutual reenforcement and to permit heat transfer from one tube to the other, whereby the temperature within the two tubes tends to equalize.

The feeder tube 3| may be fixedly secured to the'under surface of the shelf 20, whereby the shelf supports the looped portion of the tube.

The tubes 21 and 29 are of larger interior diameter than the tube9l, and therefore permit of a more-rapid expansion in the coiled portions of the conduit which encircle the chilling unit. Also, due'to-the fact that the tubes 21 and 29 are connected by solder or other heat transfer-' ring material, the temperature of the returner inflow tube 29 is kept substantially equal to that of the outflow tube 21.

' During the oif-cycle periods, ordinary evaporator coils contain liquid only in the bottom portions of the convolutions since the liquid drains from the upper portion to the lower portion as soon as the circulating force ceases. To offset this, we provide means for trapping quantities of liquid in portions of the convolutions above refrigeration.

of the I tops of the coils during the off-cycle period, but maintains a body offrost out of contact with the housing, so that air circulates downwardly over the frosted surfaces and flows along the top of the housing and down the sides there- ,of. In this manner we positively limit, or at least delay, the rise of temperature in the housing wall until the supply of trapped liquidis exhausted, and for a considerable period of time thereafter, because'of the air currents circulating around the top portions of the coils and flowing downwardly over the surfaces of the housing. This tends to maintain a body of frost on the tubes'of a more nearly constant thickness than has heretofore been possible. It prevents the accumulation from becoming suflicient to contact with the housing and shut off circulation of air around the -tubes. This advantage is in addition to the function of the trap in prolonging the period of low temperature during the off-cycle period, and in preventing a complete defrosting of the top of the coil. 1

The vertical, or side portions of the convolutions may be not only spaced from the housing,

but shields 50 may be interposed. vTherefore, if

these portions defrost during the off-cycle period relatively warm air which might otherwise'pass between them, will be excluded from the cold currents flowing downwardlyfrom the top portions within-which liquid is trappedfor continued The shields 50 may have portions offset between the paired coils to inteilock them with the coils and render them self-supporting.

A rectangular frame"comprising the rod 38,

which is preferably of plated solid material, is secured to base plate ll near the front margin the bottom. In Figure 5, this is accomplished j by depressing the top portion of the convolution,

or at least the bottom wall thereof, sufliciently to retain a quantity ofliquid subject to evapocoil portions during off-cycle periods, since vapors ization is proceeding both at the top and bottom of the coil.

As shown in Figure 1, the obliquely positioned bottom portions of the convolutions of coils 21 and 29 are soldered or otherwise secured to base plate II. By this means the side and top por- 'tions of the paired convolutions are mutually supported, with the pairs in spaced relation to each other and to the chamber l2.

Spacing refrigerating coils from the housing of a chilling unit is not novel per se, but in our improved structure, wherein liquid refrigerant is trapped in the top portions of the coils, we invoke a new principle of operation, in which the spacingot thecoils acquires added importance. The

trapped refrigerantnot only prevents defrosting and the base plate.

thereof for the purpose of adding an attractive appearance to the freezing unit. Its horizontally .extending top portion. is secured to the lower Said hanger portion 31" is'also secured to} the convolutions of the end 31 of the hanger' 31.

evaporating coil.

A control unit 36, including a mounting plate- 35, may be secured between the hangers31. The front margin of base plate II is flanged downwardly, as shown at 40, Figure 3', and its side margins are flanged upwardly as shown at H,

Figure l, to provide mounting'and sealing means for housing 12, which, together with base plate ll, form the side walls of the freezing chamber.

Housing l2 has all of its margins flanged inwardly. when the housing is in place, the flanged rear'end walls are in sealing contact withplate II, as shown at 32; Figures 1 and 2. The side wall b'ottom marginal flanges are fitted with gaskets of rubber or the like, as best, shown at 43,

Figure 4,1;0 provide a seal between the housing The front end marginal flanges are provided with a continuous gasket 44,

, Figure 4, to provide sealing means between the housing and the door 13.

Door I3 is a metal framed glass door, identical, v in construction to the evoparator unit door de-- scribed inLimpert Patent 2,158,817 and we there-.

fore do not separately-claim the door as a part of this invention.

' margin of the We provide a transversely extending slot 5 i near the front margin of the base plate H, and

we anchor therein, in lapping engagement with the walls of said slot, a strip 46 of non-heat conducting material such as rubber, for the purpose of retarding heat transfer from the front plate to the refrigerated portion at the rear of strip, we prevent the front portionof the unit,

the slot. By the provision of this including the door, from becoming as cold as the remainder of the unit, and it does not frost over upon successive opening and closing of the re-' frigerator door.

The interior of the freezing chamber is 11- translucent colored material, such as Celluloid,

but, we prefer to use one of the colored plastics which are now commercially available.

Blue colored plastic provides an eflicient filter for the red and infra-red rays, thereby excluding both the undesired color and heat which would otherwise enter the freezing chamber.

source of artificial light adjacent thereof, said evaporator having a heat insulating chamber with a wall portion adapted to admit cold light.

rays of the blue-green end of the spectrum into the chamberand to exclude the warm light rays of the red and infra-red portions of the spectrum therefrom.

2. In a chilling unit provided with a door, a heat conducting wall having one portion adjacent the door and transversely slotted to separate the portion adjacent the door from the portion reand the base. and a rear wall enclosing the end of said housing and adapted to admit rays of said artificial light from the blue-green end of the spectrum while excluding heat rays.

6. A chilling unit including a housing, a-conduit encircling the housing and comprising an outflow tube section and an inflow tube section in free communication and unitarily connected for heat exchange in counterflow relation substantially throughout their extent, the unitarily. connected sections comprising said conduit being disposed in coils about the housing having mutually spaced convolutions.

7. A device as set forth in claim 6, having top portions of the conduit depressed to trap liquid therein, whereby to maintain evaporation in both the upper and lower portions of the coils during operation of the unit in an appropriate refrigeration circuit after the supply of liquid to the unit has been cut ofl. v

8. An evaporator comprising an'outflow tube section and an inflow tube section directly coupled at one end for unimpeded flow of refrigerant through one conduit and back through the other, said tube sections having portions mutually joined for heat conduction therebetween, the joined portions of said sections extending along a general helical path throughout their extent to comprise mutually spaced convolutions of paired tubes.

9. In a refrigerator. an evaporator having a walled freezing chamber, said chamber wall ineluding a portion of light filtering and heat excluding material adapted to admit the blue-green portion of the light spectrum, and a sourceof light exterior of the evaporator for the illumination of the chamber interior by light passing through said walled portion.

mote therefrom, and a strip of non-heat con- 1 ducting material disposed in said slot to resist heat conduction from the portion adjacent the door to said remote portion.

3. The combination with the walls of a chilling unit having a linear heat conducting surface provided with a slot, of a strip of non-heat conducting material disposed within the slot and biased therein in pressure engagement with the margins of the slot whereby to retard heat transfer between portions of said wall separated by provided with an elongated transverse slot adjacent the door, a strip of heat insulating material filling the slot and adapted to check the flow of heat from the vicinity of the door to the base portion separated therefrom by said slot.

5. In a refrigerating apparatus, a freezing chamber and an adjacent source of artificial light, said chamber including the combination of a base, a removable elongated housing of U- shaped transverse section, an interior shelf supported and spaced from said base, a refrigerant conducting conduit encircling and spaced from the sides and top of the freezing chamber and having its. bottom portion rigidly securedto the base to permit heat transfer between the conduit 10. A refrigerator including a freezing unit having a chamber provided with a wall of lighttransmitting material adapted toexclude at least some heat, and a source of light exterior to said freezing unit and proximate to said unit wall, whereby light from said source penetrates the wall into the chamber-to enable the user to view the interior ofthe freezing chamber.

11. In a refrigerator, a freezing unit comprising a substantiallyclosed chamber having top, side, bottom and rear walls at least one of which comprises heat excluding, light transmitting material, and a door comprising transparent material; an evaporator associated with said chamber for withdrawing heat therefrom, and a light exteriorly proximate to said light transmitting material for illuminating the contents of the chamber and rendering them visible through the door without unduly heating them.

12. An evaporator including an open ended housing generally rectangular in cross section and disposed in a horizontal plane, and a continuous conduit encircling said housing to extend substantially the length thereof and having side,

and top portions spaced therefrom, said conduit comprising an outflow tube section and an inflow tube section in free communication and unitarily associated for heat exchange in counterflow relation substantially throughout their extent, the

unitarily associated sections being disposed in mutually spaced convolutions about said housing. 

